1. Technical Field
The present invention relates to a method of generating surround channel audio, and more particularly, to a method of generating surround channel audio for conversion into lively multichannel audio content by generating a surround channel corresponding to an input stereo channel using a trained DNN-based surround channel model.
2. Description of the Related Art
With increasing number of people who want to enjoy movies or the like in a state of higher-quality video and audio, importance of more dynamic and realistic sounds increases. Thus, people, who spare no expense in purchasing multichannel speakers or the like for projectors or large-size displays, increase, and techniques of improving immersiveness of users in the fields of communications, broadcasting and household appliances are proposed.
A multichannel audio system generally includes a front audio channel and a rear surround channel, and thus can reproduce better realism than a stereo audio system. However, since most audio content actually includes only a front audio channel, it is difficult to obtain realism due to a surround channel, when audio content is stereo audio content even though a multichannel audio system is established.
Generally, the term “surround” means to enclose surroundings and surround sound technology is sound technology developed after emergence of stereo technology expressing left and right sounds. For example, although left and right sounds need to be different since humans use both their ears, since a typical mono sound outputs only one sound, the stereo technology has been developed to supplement such a mono sound. However, although a sound from a short distance is different in feeling from a sound from a long distance, since the stereo technology cannot properly express such a feeling, surround sound technology has been developed to more realistically express surrounding sounds by supplementing stereo technology.
To realize such a surround sound, there has been proposed a method of generating a surround channel by separating a front sound recorded in stereo into multiple channels, followed by performing post-treatment such as panning and reverberation treatment for the front sound. However, since a nonlinear relationship between a front sound of actual multichannel content and a generated rear sound is not taken into account in this method, there is a problem of deterioration of realism and immersiveness in providing multichannel content.